The present invention relates generally to the field of updating electronic documents, and more particularly to updating hierarchically structured electronic documents stored in databases.
There are numerous types of electronic documents that are used in various computer applications. Often these documents have a hierarchical structure. One example of a hierarchically structured document is an extended markup language (XML) document.
As hierarchically structured data, such as XML documents, become widely used as a data format, it also becomes a native data type for database systems. The storage of hierarchically structured data in relational databases poses various challenges.
Updates to XML documents may involve operations such as deleting, inserting, replacing or modifying nodes and sub-trees, which may reduce or expand the data, depending on the nature of the operation. In addition, XML indexes must be maintained for all updates.